==
function onStart()
{
    $this['backendUrl'] = Backend::url('/');
}
==
<header class="page-header">
    <div class="page-header__inner">
        <div class="page-header__sidebar">
            <div class="page-header__menu-btn"><button class="menu-btn ico_menu is-active"></button></div>
            <div class="page-header__logo"><img src="{{ this.theme.site_logo.path|default('') }}" alt="logo"><a class="page-header__logo_text" href="/">{{ this.theme.site_name }} </a></div>
        </div>
        <div class="page-header__content">
            <div class="page-header__search">
                <div class="search">
                    <div class="search__input"><i class="ico_search"></i><input type="search" name="search" placeholder="搜索"></div>
                    
                </div>
            </div>
            <div class="page-header__action">
                {{ this.theme.top_other_link |raw }}
                <a class="profile" href="{{ backendUrl }}">登录</a>
            </div>
        </div>
    </div>
</header>